I just bought a 1990 rs 305 auto completly stock. It idles at like 1400-1500 hundred, there arent any codes getting flashed, but it is running really rich, it seems to be spraying way too much gas into throttle body at idle. The only thing that has been changed on the car is that it doenst have a cat. conv. any help would be appreciated.

 

Hey it's someone else from T-Town, can't help you with your problem just thought I'd say hey to a neighbor.

 

First seat of the pants suggestion would be to look for a cracked or disconnected vaccuum line.

 

is this at any temp?

 

whats up in t-town, yeah it does it at all temps, no vac leaks but it sucks so much air through the throttle body it sounds like a carb when the butterfies get stuck open just a little and its pouring alot of fuel into it

 

Check for a stuck PCV, IAC or EGR valve. Just getting a lot of fuel won't make it idle fast - extra air has to be getting into the manifold somewhere.

 

ok i changed pcv no difference, i blocked off egr and plugged all vac lines and it still does it anymore ideas?

 

How about the IAC valve? It's the device screwed into the throttle body on the lower rear passenger side. It controls the idle speed. With the air cleaner off, you'll see a passage on top of the throttle body right above the valve. You can block the passage off while the engine is running to see if the idle is affected. When things are working normally, blocking it off should lower the idle - possibly even stall the engine. If the idle doesn't change or stays high, air is getting in somewhere else.

Another question ... have you checked to see if the throttle goes all the way back to the stop to make sure nothing is holding it open?

 

yes it is on the stop but i will check the iac it has a new one but the pluc was boken ane the male ends are stuck in individualy ill check it out thanks

 

It was the IAC valve thanks for the help guys, now to fix it.